In a condition known as congestive heart failure, the heart cannot provide sufficient blood supply at a time when fluid is being retained in the circulation and interstitial space, as a result of pump failure. When water is retained, workload for the heart increases and oxygen supply to the heart decreases. This results in hemodynamic instability of congestive heart failure. Pulmonary wedge pressure had been used for monitoring of hemodynamic status. However, pulmonary wedge pressure measurement can be an invasive procedure typically done only in cardiac catheter centers.
What is needed is an implantable device that can monitor hemodynamic status.